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AMERICAN ELM. 

 Ulmus americana, Linnaeus. 



FORM — A large tree nsnally attaining a height ol 80-100 ft. with a diameter of 2-4 ft.. 

 but may reach a height of 120 ft. with a diameter of 8-11 feet. A tree in Jefferson county, 

 Pennsylvania, reached a height of 140 ft. and had a crown spread of 76 feet. It cut almost 

 0,000 board feet of lumber. The form is very variable. The most common Isinds which are 

 recognized are "Vase Form," "Umbrella Form," "Oak Form," and "Feathered Form." Some 

 trunits are tall and straight terminated "by a shallow but broad crown composed of very 

 gracefully drooping lateral branches. In open grown trees, the trunk often divides near 

 the ground. The form may resemble the spray of a fountain. See Fig. 35. 



BAEK — Rather thick, grayish whence Its name Gray Elm, rougher by long and irregular 

 furrows separating rather broad, flat ridges which are usually firm but occasionally flaky or corky. 

 Cross-section of bark often shows alternating white and brown layers. 



TWIGS — Slender, at first greenish and pubescent, later smooth and reddish-brown, roughened 

 by ieaf-scars and pale, inconspicuous, scattered lentlcels. Base of twigs marked with persistent 

 ring-like bud-scale scars. 



BUBS— .Alternate; terminal bud absent; ovate, sharp-pointed, slightly flattened, reddish- 

 brown, usually smooth, rarely slightly hairy, covered with about 6-10 overlapping reddish- 

 brown scales with darker margin. Leaf-buds are smaller than the flower-buds and located toward 

 end of twig. Flower-buds are larger and located along side of twig. Buds are usually 

 located above one end of leaf-scar. 



LEAVES — Alternate, simple, ovate, 4-6 inches long, thick, rough, unequally based, acute 

 at ape\, doubly-toothed on margin. Primary veins run straight from midrib to points of the 

 teeth. 



LEAF-SCARS Alternate. 2-ranked, elevated, semi-circular, with corky surface, marked with 



three oqnldlslant bundle-scars which may be componnded and are usually sunken. 



FLOWERS — Appear before the leaves from lateral propagaOve buds. Flowers occur In 3-4- 

 flowered clusters on drooping stalks about 1 Inch long. They are perfect with greenish calyx, 

 reddish anthers, and light green styles. 



FRTJIT An oval samara, about i of an inch long, borne on a slender stalk; consists of a 



flat seed surrounded by a wing which is terminally deeply notched and ciliated on margin. 

 Matures early in spring shortly after flowers. 



WOOD— Somewhat similar to Slippery Elm, page 150, but differs slightly. Weighs 40.54 

 lbs. per cubic foot, is lighter in color than Slippery Elm. and has its pores In spring wood 

 in a narrow hand of usually less than 3 rows. Its wood has a wider range of usefulness. 



DISTINGUISHING CHARACTERISTICS — The American Elm, also known as White Elm, 

 Gray Elm, and Water Elm, can readily be recognized by its leaves which are smooth on th« 

 upper surface, and by the oval fruit with ciliate margin. The flowers occur on slender droopinj 

 stalks. The buds are only slightly pubescent and covered with the chestnut-brown scales. 

 The form and method of branching are very distinctive. Also see "Distinguishing Charactej 

 istics" nnder Slippery Elm. 



RANGE— Few trees have so large a range. It extends from Newfoundland across Canada to 

 the Rocky Mountains a distance of almost 3,000 miles and south to Florida and Texas, a 

 distance of 1,200 miles. 



DISTRIBUTION IN PENNSYLVANIA— Found locally throughout the State. Most commop 

 In the well watered portions. Less frequent in the mountainous parts. 



HABITAT— Prefers rich moist bottomlands. Is commonly found along streams, bordering lakes 

 and ponds, and In rich aUuvial soil. Usually mixed with other hardwoods. 



IMPORTANCE OF THE SPECIES — The American Elm Is the most valuable of all the Elms 

 on account of its wide distribution, large size, valuable wood, and magniflcent form. Mlchaux 

 called It "the most magniflcent vegetable of the temperate zone." It has not been planted 

 much for forestry purposes but deserves to be planted, especially on rich soil which may be too 

 wet for agriculture. It must he planted close in order to prevent the development of lateral 

 branches. 



